Compilare: main.cpp: In function 'int main()': main.cpp:26:13: warning: unused variable 'a' [-Wunused-variable] int n, i, a, lin, col, d, j; ^ main.cpp:26:16: warning: unused variable 'lin' [-Wunused-variable] int n, i, a, lin, col, d, j; ^~~ main.cpp:26:21: warning: unused variable 'col' [-Wunused-variable] int n, i, a, lin, col, d, j; ^~~ main.cpp:26:26: warning: unused variable 'd' [-Wunused-variable] int n, i, a, lin, col, d, j; ^ main.cpp:28:27: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf ( fin, "%d", &n ); ^